There is known network functions virtualization (NFV) in which a function(s) of a network apparatus(es) and the like is realized as software by using a virtual machine(s) (VM(s)) implemented on a virtualization layer(s) such as a hypervisor(s) (HV(s)) on a server(s).
The European Telecommunications Standards Institute (ETSI) has been advancing a discussion on common requirements, etc. in network virtualization. At the time of filing the application, the discussion by the ETSI has completed phase 1, and now, phase 2 is underway. The result of phase 1 has been made public as literatures including NPL (Non Patent Literature) 1.
FIG. 9 is a drawing cited from FIG. 5.1 (The NFV-MANO architectural framework with reference points) on page 23 in NPL 1.
An individual virtualized network function (VNF) 22 corresponds to an application or the like that operates on a virtual machine (VM) on a server and realizes a network function as software. A management function referred to as an element manager (EM) 23 (also referred to as an element manage system (EMS)) is arranged per VNF 22. A network functions virtualization infrastructure (NFVI) 21 is an infrastructure where hardware resources of physical machines (servers) such as for computing, storage, and network functions are virtualized in virtualization layers such as hypervisors to be flexibly used as virtualized hardware resources such as for virtual computing, virtual storage, and virtual networks.
An NFV orchestrator (NFVO) 11 of an NFV management & orchestration (NFV-MANO) 10 performs orchestration of resources of the NFVI 21 and lifecycle management of network service (NS) instances (instantiation, scaling, termination, update, etc. of NS instances). In addition, the NFVO 11 manages an NS catalog 14 (NSD/VLD/VNFFGD) and a VNF catalog 15 (VNFD(VNF/PNFD)) and has an NFV instances repository 16 and an NFVI resources repository 17.
A VNF manager (VNFM) 12 performs lifecycle management of VNF instances (for example, instantiation, update, query, scaling, termination, etc.) and event notification.
A virtualized infrastructure manager (VIM) 13 manages computing, storage, and network resources of the NFVI 21, monitors a failure of the NFVI 21, and monitors resources of the NFVI 21, for example.
“Operations service systems (OSS)” of an OSS/BSS 30 is a general term for systems (apparatuses, software, mechanisms, etc.) needed by, for example, telecommunication carriers (carriers) to establish and operate services. “Business support systems (BSS)” is a general term for information systems (apparatuses, software, mechanisms, etc.) needed by, for example, telecommunication carriers (carriers) to use for charging usage fees or the like, billing, customer care, etc.
The NS catalog 14 represents the repository of network services (NSs). The NS catalog supports the generation and management of network service (NS) deployment templates (a network service descriptor (NSD), virtual link descriptor (VLD), and VNF forwarding graph descriptor (VNFFGD).
The VNF catalog 15 represents the repository of on-boarded VNF packages, for example. The VNF catalog 15 has a VNF descriptor (VNFD), PNF descriptor (PNFD), etc.
The NFV instances repository 16 holds information about all VNF instances and network service (NS) instances. The VNF instance and the NS instance are described in VNF and NS records, respectively. These records are updated during the lifecycles of the respective instances, reflecting execution results of VNF lifecycle management operations and/or NS lifecycle management operations.
The NFVI Resources Repository 17 holds information about available/reserved/allocated resources of the NFVI 21, the information abstracted by the VIM 13, and provides useful information, for example, for reservation, allocation, and monitoring of resources. The NFVI resources repository 17 is important, for example, in the resource orchestration of the NFVO 11, since the NFVI resources repository 17 can track the reserved/allocated resources of the NFVI 21 against the NS and VNF instances associated with these resources (e.g., the number of virtual machines used by a target VNF 22 at any time during its lifecycle).
In FIG. 9, a reference point Os-Ma-nfvo is a reference point between the OSS/BSS 30 and the NFVO 11 and is used, for example, for:                network service lifecycle management,        a VNF lifecycle management request, and        forwarding of NFV-related state information and exchange of policy management information.        
A reference point Vi-Vnfm is used for:                a resource allocation request from the VNFM 12 to the VIM 13, and        exchange of configuration and state information about virtualized resources.        
A reference point Ve-Vnfm-em is used between the EMS 23 and the VNFM 12, for example, for:                VNF instantiation, VNF instance query, update, termination, scaling out/in, scaling up/down, and        configuring VNFM12 form EM (EMS) 23, forwarding of an event and notification of a VNF configuration from the VNFM 12 to the VNF 22 or an event.        
A reference point Ve-Vnfm-vnf is used between the VNF 22 and the VNFM 12, for example, for:                VNF instantiation, VNF instance query, update, termination, scaling out/in, scaling up/down, configuring the VNFM from the VNF, forwarding of an event, and notification of a VNF configuration from the VNFM 12 to the VNF 22 or an event.        
For example, in addition to instructions about computing/storage resources, a reference point Nf-Vi is used for allocation of virtualized resources to a resource allocation request, forwarding of state information about virtualized resources, and exchange of configuration and state information about hardware resources, such as allocation of a virtual machine (VM), update of VM resource allocation, VM migration, VM termination, and generation/removal of connection between VMs.
A reference point Vn-Nf represents execution environment provided by the NFVI 21 to the VNF 22.
A reference point Or-Vnfm is used for:                resource-related requests by the VNFM 12 (authorization, reservation, allocation, etc.), forwarding of configuration information to the VNFM 12, and collection of VNF state information.        
A reference point Or-Vi is used for:                a resource reservation request from the NFVO 11 to the VIM 13 (reserve resource request), a resource allocation request (allocate resource request), and exchange of configuration and state information about virtualized resources (see NPL 1 for the details).        
The network service descriptor (NSD) of the NS catalog 14 is a network service deployment template and has an entity that defines network function scripts/workflows of specific lifecycle events (instantiation, termination, scaling, etc.).
The VNFFGD (VNF Forwarding Graph Descriptor) is a deployment template which describes a network service topology or a part thereof by referring to VNFs, PNFs, or virtual links connecting these VNFs and PNFs.
The Virtual Link Descriptor (VLD) is a deployment template which describes the resource requests that are needed for a link between VNFs, PNFs, and NS endpoints available in the NFVI 21.
The VNF Descriptor (VNFD) of the VNF catalog 15 is a deployment template which describes a VNF in terms of its deployment and operational behavior requirements. The VNFD is primarily used by the VNFM 12 in the process of VNF instantiation and lifecycle management of a VNF instance. The VNFD is used by the NFVO 11 to manage and orchestrate network services and virtualized resources on the NFVI 21 (computer system/middleware/service deployment/setting/management automation). The VNFD also contains connectivity, interface, and Key Performance Indicators (KPI) requirements that can be used by the NFVO 11 to establish virtual links between VNFC instances of the NFVI 21 or between a VNF instance and an endpoint of another network function.
The Physical Network Function Descriptor (PNFD) of the VNF catalog 15 describes the connectivity, interface, KPIs requirements of virtual links to an attached physical network function. This is needed if a physical device is incorporated in an NS and facilitates network expansion.
The OSS/BSS 30 or the VNFM 12 performs NS or VNF instantiation operations on the NFVO 11. As a result of the instantiation operations, records representing newly generated instances are generated. For example, the records generated based on the information given in the individual descriptors and additional runtime information related to the component instances provide data to model the network service (NS) instance states. Examples of the generated instance records include:                network service record (NSR),        VNFFG record (VNFFGR),        virtual link record (VLR),        virtualized network function record (VNFR), and        physical network function record (PNFR).        
The NSR, VNFR, VNFFGR, VLR information elements provide a collection of data items that are needed to model the states of instances of an NS, VNF, VNFFG, and VL. The PNF record forms a part of an NS, represents an instance relating to a PNF that has pre-existed, and includes runtime attributes regarding PNF information (connectivity relevant to the NFVO).    NPL 1: ETSI GS NFV-MAN 001 V1.1.1 (2014-12) Network Functions Virtualisation (NFV); Management and Orchestration (searched on Apr. 12, 2016)